I have been conditioning an imperial stout with 4oz of nibs that had been soaked for 3 days in about 3-4ozs of vodka. Its been 4weeks and there is a slight alcohol burn present that is distracting to the flavor. Although this is an Imperial Stout style it did not have that alcohol burn before the nib addition.

Long winded. Question. Will this burn fade over time or during bottle conditioning? It has not been bottled yet.

It should fade over time. Try any beer that's been barrel aged fresh, then try it a year later and you'll be amazed at how much smoother its gotten over that time. I'm not saying you have to wait a year for this beer to be ready, but go ahead and let it mature. Crack one open every now and then and see how you like it.

Possibly. I doubt that 3 ounces in 5 gallons of beer would have much effect on flavor when it comes right down to it. Vodka is such a flavorless form of alcohol to start with and 3 ounces is just a tiny amount.

I suspect you just happened to be more sensitive the second time you tasted it. And a big beer will usually require weeks of aging before some of the alcohol burn starts to fade. Give it time and it will improve.

Cheap vodka will be slightly less flavorless than a smoother, more expensive brand, but really, 3 ounces is a small amount.

As long as it isn't harsh fusels (which should not be present in commercially produced distilled liquor - the distillation process allows for the distiller to easily separate fusel alcohols from the main product), it will fade over time. That said, 4 oz. is a very small addition of distilled liquor and I would be surprised you could taste it as anything at all even if you had added all of it.

I once did an Imperial Stout with 8 oz. of nibs soaked in vodka overnight and then added the vodka in. It had an *intense* chocolate aroma months and months after brewing, but the beer had an acidic flavor that I couldn't really place.

It's not the vodka. 4 oz of vodka would contribute less than 0.3% ABV to your beer- not noticeable. I would look to your fermentation practices for sources of fusel alcohol.

Absolutely 4oz of cheap vodka could influence the flavour of the beer. Alcohol content doesn't tell the entire story; I mean hell, think how many people get a quite noticeable bourbon character doing bourbon porters/stouts with that much hard alcohol. You really don't think cheap, fusel-ridden vodka with a noticeable hard alcohol burn ISN'T going to be noticed? There's a reason why the rule of thumb on this kind of thing is to not use hard alcohol you couldn't stomach drinking otherwise. Further, he already stated the flavour wasn't there before adding the nibs, so I think it's safe to say the vodka is the likely source of the burn.

Absolutely 4oz of cheap vodka could influence the flavour of the beer. Alcohol content doesn't tell the entire story; I mean hell, think how many people get a quite noticeable bourbon character doing bourbon porters/stouts with that much hard alcohol. You really don't think cheap, fusel-ridden vodka with a noticeable hard alcohol burn ISN'T going to be noticed? There's a reason why the rule of thumb on this kind of thing is to not use hard alcohol you couldn't stomach drinking otherwise. Further, he already stated the flavour wasn't there before adding the nibs, so I think it's safe to say the vodka is the likely source of the burn.

4 oz. is less than three shots of vodka and regardless of how cheap the vodka is, vodka by definition is flavorless, whereas bourbon and whiskies have a moderately strong flavor. Moreover, the original poster stated just above that he decanted the vodka before adding the nibs.